Electrostatic coating systems in which a charged workpiece is moved by a conveyor through a coating zone have typically had physical contact between the workpiece support and a charged conductor. Such systems are subject to sparking which is undesirable. Systems have been proposed in which an electrostatic charge is induced on a workpiece by moving the support therefor adjacent a charged wire. The support in such systems is free to swing toward and away from the charged wire. This results in a variation of the magnitude of charge on the workpiece, degrading the quality of the coating. Sparking may occur if the support approaches the charged wire too closely.